Welding material

ABSTRACT

A consumable welding material particularly suitable for welding products nominally containing nickel-28% chromium-10% iron, comprising, by weight, about 27% to 31.5% chromium, about 5% to 14% iron, about 0.5% to 1.1% aluminum, about 0.1% to 0.7% titanium, about 0.02% to 0.08% carbon, up to about 0.1% magnesium, up to about 0.010% nitrogen and the balance nickel and incidental elements. The welding material provides substantially sound, corrosionresistant weld deposits.

United States Patent Petersen Nov. 11, 1975 i 1 WELDING MATERIAL 35mmtombs tssn 119x145 ['75] Inventor: Walter Adrian Petersen.

Rldgewood Ni Primal-t l;'.\um1'IwrC. L. Albritton [73] Assignee; h lm mNick compdmh .-l.s:\'[.wum IiMIHriIItW-Clitford C Shun New York NY:lIIrH'm't. Agent. or 'irm-Mirium W. Left; Ewan C. MucQueen [22] Filed:July 27, 1973 [2|] Appl. No: 383,380

Related US. Application Data [57] ABSTRACT l 1 N0 Jm 7 W7 A consumablewelding maternal purtlculurl} suitable for welding products nominullcontaining nickel-28% 2] U.S C| H 219/137; 219/145 chromium-1U? iron.comprising. b weight. about 1] Int Cl 323k 9/02 2792 to 31.592 chromium.about 592 to 14)? iron.

8] Fie'd of Search n Zlwmi 137 about 0.5% to 1.1 aluminum. about 0.1% to(1.7%

titanium. about (1.02 to (M1892 eurbon. up to about (56] References and0.1% magnesium. up to about (LLHUJ? nitrogen and UNITED STATES PATENTSthe balance nickel and incidental elements. 1 184577 W965 Wuhan)" 119MThe welding mnteriul provides substuntiull sound. 55861615 lT/Wofi Knutzct .iifff, QI QI QII Emmi FOREIGN PATENTS OR APPLlCATlONS l Clahm N0Drawings 987.6[6 3/1965 United Kingdom..............,.. ZlJ/Hfi WELDENQMATERIAL The present application is a division of application Ser. No,221,400, filed Jan, 27, 1972 now US. Pat. No. 3,770,427.

The present invention relates to nickel-base welding materials and, moreparticularly, to nickel-chromiumiron filler metal for insert gasshieldedarc welding.

Nickelbase alloy materials nominally including, by weight, nickel, about28% chromium and about 10% iron, e.g., those of the type disclosed inU.S. Pat. Nos. 3,565,6ll and 3,573,90l issued to Economy on Feb. 23,1971and Apr. 6, 197 l respectively, and 3,574,604 issued to Copson and VanRooyen on Apr. 13, 1971, are commercially desirable, inter alia, becauseof their good corrosion resistance, particularly in environments such ashigh cmperaturc, high-pressure water contain ing lead or environmentscontaining chloride ions; caustic materials; or nitric acid. Suchnickel-base alloys nominally containing 28? chromium and 10% iron caninclude, for example, by weight, about 27% to 31% chromium, about 7% toabout lift iron, up to about 0.05% carbon, up to about 0.5% silicon, upto about 0.5% manganese, about 0.1% to about 0.4% aluminum, about 0.17to about 0.5% titanium, about 0.005% to about 0.065 magnesium, about0.00l7n to about 0.0l% boron, up to about 0.292 copper and the balanceessentially nickel. it is often desirable from the standpoint of costand reliability. that structures and/or parts made with various shapes,cg, sheet, plate, strip, rod, pipe, etc., of these nickel-base alloymaterials be fabricated by welding, it being necessary in manyapplications that the corrosion resistance of the welded joints becomparable to that of the parent metal. However, when welded joints aremade using filler material of the parent alloy composition, excessiveweld cracking is observed. For example, butt wclds made in linch thickair-melted base plates containing, by weight, 29.9% chromium, 8.6% iron,007.1% carbon, 0.16?! manganese, 0.0l47t magnesium, less than 0.02%silicon, 0.004% oxygen, 0,0006% hydrogen, 063.5% nitrogen, and thebalance essentially nickel, using filler metal of matching compositionand a downhand manual gas tungsten-arc technique, exhibit, at Xmagnification, an average of 4.7 cracks per section in the as-weldedcondition, in transverse slices polished and etched with Lcpitosreagent. These cracks have lengths not exceeding one-cighth inch. Two ofthe transverse slices cut from these welds, polished and etched withLepitos reagent and then subjected, in the as-welded condition, to sidebend tests, which involve bending the weld area of the slice I80" abouta li -L; inch diameter (4 times the slice thickness) pin exhibited anaverage of 26.0 cracks per section at l0 magnification.

On the other hand, we ds made with presently available commercial,non-matching nickel-chromium-iron alloy filler material exhibitsoundness when used with parent metal typically having the above nominalcornposition, but do not always offer adequate corrosion resistance.

It has now been discovered that sound weld joints cxhibiting goodcorrosion resistance can be produced in materials nominally containingnickel- 894 chromium 10% iron by employing a special nickeLChromium-ironalloy welding material. The special welding material provides desirableresults when used to weld various mill forms, plates, strip, tubing,rod, etc, of such composition lo each other or to shapes ofsignificantly different composition and can be used to provide overlays.

it is an object of the present invention to provide an improved weldingmaterial that provides relatively sound, corrosion-resistant weldedjoints.

Another object is to provide an improved welding material particularlysuitable for welding parts, containing, nominally, nickel-28%chromiumlO7z iron.

Still another object is to provide an improved welding materialcomposition exhibiting good hot workability.

Generally speaking, the present invention contemplates a consumablewelding filler material usable in arc welding processes, includingmanual and automatic gasmctal arc welding, manual and automatic gastungsten-arc welding, and inert gas shielded-arc and submergcd-arcwelding, such welding material containing, by weight, at least about27%, but not more than about 3l.571. chromium; about 5% to about I49more preferably, about 8": to about 11%, iron; about 0.5% to about 1.19?aluminum, about 0.1% to about 0.7% titanium; up to about 0.1% ofmagnesium; about 0.059% to about 5% manganese; about 0.029? to about0.08% car boil; and the balance nickel and incidental impurities.Nitrogen may be present in the wire but preferably is limited to amountsless than about 0.030% and more preferably less than about 0.01%.

The welding electrode can also include up to about 0.3% silicon, up toabout 0.57: copper, up to approximately 0.01% oxygen, up to about 00W?sulfur, up to about 0.01% phosphorous and up to approximately 0,00l/rhydrogen. Preferably, the material is substantially devoid of boron.zirconium, cobalt, columbium, molybdenum and tungsten although amountsup to each 0.1% zirconium, 6% cobalt, 292 molybdenum, and 2% tungstenmay be present. Larger amounts of these elements may lead to excessiveweld cracking,

Welds produced with welding material provided in accordance with thepresent invention, are substantially free of cracks and porosity, evenwhen relatively thick, e.g., l inch, materials are welded, and exhibitcorrosion resistance comparable to that of the parent metal of the typehaving a nominal composition of nickel -lllli chromium-10% iron.

It is essential that all of the foregoing ingredients of the weldingmaterial composition be present in the amounts specified in order toprovide useful operatiing characteristics during welding and sound weldshaving good mechanical properties and to provide the further benefit ofexcellent corrosion resistance in severely corrosive environments. Forexample, the chromium level ofthe wire should be at least about 27weight percent so that welds made therefrom will be corrosion resistant,eg, will be substantially free from cracking, when exposed toenvironments such as those common to high-temperature, high-pressurcwater systems, e.g., those environments found in nuclear reactors.Chromium levels significantly exceeding about 31.5% are not desirable,however, because such amounts can lead to the formation ofundcsirablcprecipitates, cg, alpha chromium, resulting in unsound welds andimpaired corrosion resistance in lead-contaminated water envi moment.The presence of both titanium and aluminum in the welding material inthe amounts specified is neccssary to provide weld soundness in both theas-welded condition and in the aged condition. It is found that thenumber of weld cracks increases significantly as the titanium andaluminum levels are decreased below the respective lower amountsspecified therefor, Titanium 600 A h example f an ll h can b ld d andaluminum levels higher than those specified have to the above types ofcompositions or to itself, using the been found to lead to cracking inthe cold working p" welding wire of the invention, is low alloy steel.erations commonly associated with wire processing. It F h purpose f i ithose kill d i h t 3 appears that aluminum contents on the order ofabout 5 better understanding f h i ti d a b tt 0.5% to about 0.7% arebeneficial in gas-shielded metpre iation of h advantages h f h f ll ial-arc welding. amples are given.

Magnesium desirably is present in the filler material PLE 1 in an amountup to 0.1% as a malleabilizer to prevent cracking during hot working ofthe material. A small residual magnesium content in the weld. which maybe on the order of up to about 0.03% appears to be of assistance inavoiding weld reheat cracking; i.e., cracking due to the heat fromsubsequent weld passes. The nitro- 15 gen content ofthe welding. orfiller, material preferably is low to minimize the propensity to weldcracking, particularly where the weld is to be subsequently aged. Inthis respect. it is preferred that the welding material be produced byvacuum melting techniques so as to mini- 2 mize nitrogen content.

Filler wire having the composition shown in Table l was produced byvacuum melting in a 50 kilowatt in duction furnace, a charge of 28.5kilograms of Mond nickel shot and 4.8 kilograms of electrolytic iron.after which 13.68 kg. of Vacuum Grade low-carbon chromium, 72 grams ofelectrolytic manganese, and 72 grams of metallic silicon were added tothe molten charge, and the charge then held for 30 minutes under vacuumat 2850 to 2900F. Then 240 grams of highcarbon chromium was added to thecharge and the furnace backfilled to 1b atmosphere argon, after whichthere were sequentially added to the molten charge,

Carbon levels of the welding material should be 34 grams f aluminum d240 grams f i i m maintained above about 0.02 weight percent to avoidSponge, and 194 grams f i k magnesium weld deposit Cracking but belowabout Weight ter alloy. The molten charge was then poured into a percentto limit excessive corrosive attack on the weld Cast i i m ld Th ingotswam hi d to g P ang n in HmOUnIS P IO about 56/! i8 move the surfacelayer and then soaked at 2250F. for sired in the welding materialproduced according to the 2 h hot rolled to 2 inch square bars, reheatedat invention to reduce susceptibility to weld cracking, the 2250 F., androlled to /s-inch square rod, which rod preferred amount of manganesebeing at least about was cold rolled and swaged to filler wire having adiam- 0.05%. eter of oneeighth inch.

TABLE I Filler Wire Composition (WLQ )(a) (r Fe Al Ti Si Mn Mg C Ni 29.3l l.7 0.7l 0.54 0.18 0.07 0.024 0.062 Bal.

ta) Also contains 000.18% Oxygen. 0.000199; Hydro en and 000589;Nitrogen While various iron contents over the range of about Manual gastungsten-arc butt welds (hereinafter re- 5% to 14%, by weight, appear toprovide comparable ferred to as Weld Numbers l and 2) were made in oneresults with respect to the absence of weld cracking, inch thick platesof, respectively, a vacuum melted welds produced with welding materialcontaining less alloy and f a C mm r ial air-m lt d alloy. The Weldsthan 5% iron exhibit poor corrosion resistance in leadr made u ing afill r m ri l Va-inch diameter wire contaminated water while thoseproduced with welding of the Composition Show" in Table TheVacuummaterial with more than l4% iron exhibit inadequate melted Platecontained about 285% Chromium about corrosion resistance in causticenvironments. 103% iron, aboul 003% aluminum, aboul 001070 Silicon canbe present in the welding material in about 005% magnesium, less thanaboui 005% amounts up to about0.3% withoutany apparent effects siliconabout 048% titanium about 0-l5% mauga" on he performance Ofthe finerwire nese, 0.0084% oxygen, 0.00018% hydrogen, 0.017%

The wading material produced according to the nitrogen and the balanceessentially nickel, and the air pmsem invention can be in the form offor example. melted plate of commercial origin contained 29.8% SheetStrip tube Gr wire. chromium, 8.6% iron, 0.14% aluminum, 0.29% titalnaddition to its use in welding together various parts 016% manganese00217 00|4% nesium, less than about 0.02% silicon, 0.0039% oxy gen,0.0006% hydrogen, 0.0635% nitrogen, and the balance essentially nickel.These plates were in the hotrolled and annealed (2l00F. for 1 hour andwater quenched) condition, as were the plates of the following examples.The above welds were made in the flat position at about 230 amperesdirect current, straight polarity (DCSP) and 16 volts and were completedin 24 passes, the travel speed being approximately 3 inches per minute.Each of the plates measured 3 by 4 inches by 1 inch thick and had a 15bevel along one 4-inch edge, blended to a 3/32-inch root face by a/4-inch radius. The plates were heavily restrained with U-clamps havingthe above nominal composition, i.e., 28% chromium, 10% iron, balanceessentially nickel, the welding material produced according to thisinvention can be used to weld such parts to other parts generally havingdifferent composition. Such parts of different composition can include,by weight, up to about 50% iron, about 14% to about 35% chromium, up toabout 6% each of manganese, copper, cobalt and columbium, up to about0.15% carbon, up to about 2% titanium, up to about 4% aluminum, up toabout 3% each of vanadium and tungsten, up to about 2.5% silicon, up toabout I% tantalum, up to about 10% molybdenum and the balanceessentially nickel. Examples of alloys within this compositional rangeare l8-8 stainless steel and Alloy to a 3-inch thick copper-faced steelplaten during welding, such restraint and the relatively thick platesbeing considered to provide severe welding conditions.

The weld deposits in the vacuum-melted plate typically contained 0.036%carbon, 0.08% manganese, 015% silicon, 28.0% chromium, 0,59% aluminum,0.43% titanium, l0.0% iron, 0.003% magnesium, 0.002l% oxygen, 0.000l9%hydrogen, 0.0l20% nitrogen, and the balance nickel, while the welddeposits in air-melted plates typically contained 0.035% carbon, 0.09%manganese, 0.14% silicon, 28.3% chromium,

The two %-inch wide transverse slices cut from each of the two welds,i.e., Weld Nos. 1 and 2, were tensile tested for room temperaturemechanical properties, the test specimens being cut to locate the weldin center ofthe gauge length. The test results are given in thefollowing Table II which also provides the properties of unweldedair-melted base plate of comparable composition to that of theair-melted plate described hereinbefore, in the hot-rolled andhot-rolled and annealed (d IFracture at weld *lksil I000 pounds persquare inch 0.58% aluminum, 0.46% titanium, 9.6% iron, 0.003% magnesium,0.0024% oxygen, 0.000150% hydrogen, 0.0l60% nitrogen and the balancenickel.

Radiographic examination of these welds indicated them to be free ofdefects. Each of the plates was cut transversely through the weld intotwo A-inch and four %-inch thick slices inclusive of a weld section,each such slice then being polished on a rubber-bonded abrasive wheel,macro-etched with Lepitos reagent and then macroscopically examined at amagnification of 10X. In 14 faces that were examined, the welds in thevacuum-melted plate material exhibited only one crack and that was lessthan 1/32-inch long, for an average of 0.07 cracks per section, whilethe air-melted commercial plate weld exhibited, in [4 faces examined,three cracks that were individually shorter than l/32-inch for anaverage of 0.2 cracks per section.

Two of the four 56-inch wide transverse slices cut from each of the twowelds (Nos. 1 and 2) were given a post-weld aging treatment by heatingfor hours at l300F. and air cooling. These aged slices, as well as two%-inch wide slices from each of the welds in the aswelded condition,were etched with Lepitos reagent, side-bend tested, and examined tofurther determine their weld soundness. The side-bend tests consisted ofbending the various transverse slices 180 about I); inch diameter (4Xspecimen thickness) pin. Because of the deformation involved in bendingthe weld specimen, cracks, fissures and other defects become morereadily apparent so that examination of bend-tested welds is consideredto be a relatively severe test for weld soundness. The aging treatmentis considered to further increase the severity of the bend test. Onmacroscopic examination of the side-bend tested specimens at 10Xmagnification, the welds in the slices from the commercial air-meltedplate contained, on the average, l.0 cracks per section for theas-welded condition and 1.5 cracks per section for the aged condition,while the slices from the vacuum-melted plate showed no cracking ineither the as-welded or aged condition. The low incidence of cracks inthe air-melted commercial plate is well within the allowable limits forthis class of welding material, as specified in MlL-E-2l562B (Ships).These results show the satisfactory results obtainable with filler wireproduced according to the present invention.

From these results, it can be seen that the yield strengths of the weldswere higher than that for the annealed plate and about the same as thehot rolled plate, while the ultimate tensile strengths of the weldscompared favorably with those for the plate material in both conditions.

EXAMPLE II To evaluate plate welds between a nickel-base alloy of theabove-mentioned nominal composition (i.e., nickel-28% chromium-l0% iron)and an alloy of dissimilar composition, the filler wire described inExample I was used to butt weld a commercial, air-melted one inch thickplate of the same composition and con figuration as that described inExample I, to similarly beveled plates of Alloy 600 (a nickel-base alloynominally containing about [5.5% chromium and 8% iron) and of Type 304stainless steel (l8% chromium, 8% nickel and balance iron). The weldingwas done under conditions similar to those in Example I, i.e., downhand(flat position) manual gas tungsten-arc welding employing 230 amperesDCSP and [6 volts, the welds being completed in 24 passes each. The weldto the Alloy 600 plate contained 0.037% carbon, 0,10% manganese, 27.9%chromium, 9.7% iron, 0.54% aluminum, 0.49% titanium, 0.078% silicon,0.002% magnesium, 0.0023% oxygen, 0.000l4% hydrogen and 0.0150%nitrogen, while the weld to the stainless steel plate contained 0.036%carbon, 0.l7% manganese, 27.2% chromium, 12.9% iron, 0.55% aluminum,0.45% titanium, 0.l3% silicon, 0.005% magnesium, 0.003l% oxygen,0.00009% hydrogen and 0.0l% nitrogen.

Raidographic examination of each of these welds did not reveal anydefects therein. The welded plates were sliced transverse to the weld,polished and macroetched with Lepito's reagent in the manner describedin Example I. Macroscopic examination at 10X magnification of theseetched slices in the as-welded condition disclosed an average number of0.3 cracks per section in the weld to the Alloy 600 and no cracks in theweld to the Type 304 stainless steel.

Side bend tests were performed on one group of these slices, each ofwhich was in the as-welded condition and had a iii-inch thickness, andon a third group of these slices of the same thickness that had beenaged, after welding, at 1300F. for 20 hours and air cooled. All of theslices were etched with Lepitos reatransversely to the weld, polished ona rubber-bonded abrasive wheel and etched with Lepi'tos reagent, asdescribed in Example 1. Macroscopic examination of 14 transverse facesat 10X magnification revealed no t b fore the bend test was performed.The bend cracks to be present. Side bend tests were performed tests wereconducted in the manner described in Examin th manner de ribed inExample I on %-inch thick ple l. The bend test specimens were thenexamined for slices cut from the welded plates, polished and etched weldcracks at l0 magnification. The weld between with Lepitos reagent, theseslices being in the asthe commercial plate and the plate of Alloy 600exhiblded ondition and in the aged (l300F,/20 hours ited no cracks inthe as-welded condition and an avcrnd i o l d) ondition, The thus-testedsli es were age number of only 1.0 Cracks per Se on in the g thenexamined at 10X magnification. Only one of the condition. while the weldbetween the commerci two as-welded bend test specimens showed a singleplate and the plate of Type 304 stainless steel exhibited ra k, for naverage number f0 5 cracks per section, an average number of only 1.0Cracks per E i n in while the aged bend-test specimens were free fromeach of th as-w l d a d ag Conditions 15 cracking, thus indicating theusefulness of the tiller Th8 abm'e-descrlbed Wfildfll Plales alsoexhibited metal produced according to this invention,for the gasgoodmechanical properties in both the as-welded and hi ld d metals; ldingpro e aged condition, as seen from the results in Table 111, where theAlloy 600 plate welds and the stainless steel EXAMPLE 304 W ds. re pctive y. are referred 10 a8 Weld 3 To determine the corrosion resistanceof welds made and 4. The test specimens were lb-inch thick slices cut ih fin i d d according to h present i from the respective welded plates.vention, air-melted filler wire containing, by weight,

Table [[1 Weld Yield Strength Ultimate Elongation Reduction Fracture No.(0.2% offset) Tensile In Area Location (ksil* Strength (7%) (ksi)* AsWelded 3 52.4- 904 32.5 55.5 Weld 4 53.7 84.7 33.5 68.8 Base Metal Aged(130(IF./20 hrs. Air Cooled) 3 48.8 94.7 23.5 62.0 Base Metal 4 43.584.1 28.5 745 Base Metal lksil 1000 pounds. per square inch The aboveresults indicate the ability to provide satisfactory welded joints withfiller wire produced according to the present invention, between analloy nominally containing nickel-28% chromiun-l0% iron and dissimilaralloys, such as Type 304 stainless steel or Alloy 600.

EXAMPLE 111 To determine the versatility of filler wire of the presentinvention, 0.062 inch diameter filler wire prepared from a laboratoryair-melted heat produced with raw materials of high purity, containing27.8% chromium, 10.4iron, 0.056% carbon, 0.16% manganese, 0.14% silicon,098% aluminum, 0.12% titanium, 0.053% magnesium, about 0.0002% hydrogen,about 0.015% oxygen. about 0.020% nitrogen, and the balance essentiallynickel was used to produce a butt weld, using the automatic gas-shieldedmetal-arc welding process, between air-melted one inch thick platescontaining about 28.9% chromium, about 10.9% iron, about 0.067% carbon,about 0.25% manganese, about 0.21% silicon, about 0.08% aluminum, about0.31% titanium, about 0.02% magnesium, about 0.0006% oxygen, 0.00007%hydrogen, about 0.0365% nitrogen, and the balance essentially nickel.The weld was completed in 8 passes using 300 amps, 32 volts, and 10inches per minute travel speed. The weld composition was 28.2% chromium,10.8% iron, 0.026% magnesium, 0.068% carbon, 0.19% manganese, 0.16%silicon, 0.71% aluminum, 0.17% titanium, 0.0105% oxygen, 0.000l9%hydrogen, 0.0385% nitrogen, and the balance essentially nickel. No weldcracks were detected on radiographic examination of the weld. The weldedplates were sliced 27.7% chromium, 10.3% iron, 0.050% carbon, 0.15%manganese, 0.19% silicon, 0.52% aluminum, 0.68% titanium, 0.064%magnesium, 0.0097% oxygen, 0.023% nitrogen, about 0.0002% hydrogen, andthe balance essentially nickel, was used to produce a butt weld in 1-inch thick hot-rolled, airmelted plate containing about 28.9% chromium,about 10.9% iron, about 0.067% carbon, about 0.25% manganese, about0.21% silicon, about 0.08% aluminum, about 0.31% titanium, about 0.02%magnesium, about 0.0365% nitrogen, about 0.0006% oxygen, about 0.00007%hydrogen and the balance essentially nickel. The butt weld, was producedby downhand, manual, gas-shielded tungsten-arc weld methods using 220amps, 16 volts with an estimated travel speed of 3 inches per minute andwas radiographically sound. Pieces cut from the welded plate wereimmersed in boiling 65% nitric acid for five sequential periods of 48hours each. No preferential attack was noted in the weld areas and thegeneral corrosion rate was equivalent to that of the base alloy. Thesesame slices from the welded plate, which were deformed to double U-bendspecimens and tested for 48 weeks in aerated and de-aerated water of pH10 (adjusted with NaOH) at 600F., exhibited no apparent intergranularcracking or accelerated corrosive attack. The double U-bend specimenswere made by simultaneously bending two coinciding slices, each havingapproximate dimensions of is by by 3% inches, over a 94-inch diametermandrel so that the weld deposits were located at the apex of the bend.

Although the present invention has been described in conjunction withpreferred embodiments, it is to be understood that modifications andvariations may be resorted to without departing from the spirit andscope of the invention as those skilled in the art will readilyunderstand. Such modifications and variations are considered to bewithin the purview and scope of the invention and appended claims.

I claim:

1. A method of producing relatively crack-free, corrosion-resistant weldjoints between metal pieces wherein at least one of the pieces to bejoined by welding contains about 28% chromium, about 10% iron. and thebalance essentially nickel and incidental constituents, said methodcomprising gas-shielded are welding said pieces with filler metalconsisting essentially of, by weight, about 27% to about 31.5% chromium.about 5% to about 14% iron. about 0.5% to about l.l% aluminum, about0.1% to about 0.7% titanium, up to about 0.l% magnesium. about 0.05% toabout 5% manganese. about 0.02% to about 0.08% carbon, up to about 0.3%silicon, up to about 0.5% copper. up to about 0.030% nitrogen, up toabout 0.1% zirconium, up to about 6% cobalt, up to about 2% molybdenum,up to about 2% tungsten, up to about 0.01% each of phosphorus and sulfurand the balance essentially nickel.

1. A METHOD OF PRODUCING RELATIVELY CRACK-FREE, CORROSIONRESISTANT WELDJOINTS BETWEEN METAL PIECES WHEREIN AT LEAST ONE OF THE PIECES TO BEJOINED BY WELDING CONTAINS ABOUT 28% CHROMIUM, ABOUT 10% IRON, AND THEBALANCE ESSENTIALLY NICKEL AND INCIDENTAL CONSTITUENTS, SAID METHODCOMPRISING GASSHIELDED ARC WELDING SAID PIECES WITH FILLER METALCONSISTING ESSENTIALLY OF, BY WEIGHT, ABOUT 27% TO ABOUT 31.5% CHRONIUM,ABOUT 5% TO ABOUT 14% IRON, ABOUT 0.5% TO ABOUT 1.1% ALUMINUM, ABOUT0.1% TO ABOUT 0.7% TITANIUM, UP TO ABOUT 0.1% MAGNESIUM, ABOUT 0.05% TOABOUT 5% MANGANESE, ABOUT 0.02% TO ABOUT 0.08% CARBON, UP TO ABOUT0.030% % SILICON UP TO ABOUT 0.5% COPPER, UP TO ABOUT 0.030% NITROGEN,UP TO ABOUT 0.1% ZIRCONIUM, UP TO ABOUT 6% COBALT, UP TO ABOUT 2%MOLYBDENUM, UP TO ABOUT 2% TUNGSTEN, UP TO ABOUT 0.01% EACH OFPHOSPHORUS AND SULFUR AND THE BALANCE ESSENTIALLY NICKEL.